Influence of the MgO content on zirconia-toughened alumina ceramic slurry properties and sintered body microstructure

Abstract

Complex ceramic components fabricated using the Vat photopolymerization ceramic 3D printing technology (VPP) exhibit mechanical anisotropy both within and between the printed layers. To address this issue, the effects of different MgO vol% on the self-leveling properties, green body forming characteristics, microstructure of the sintered bodies, and mechanical properties of ZTA ceramic slurries were investigated. The results indicate that the layered structure of the ceramic component significantly improved with the addition of 0.75 vol% MgO. The fabricated MgO–ZTA ceramic gear exhibited high surface precision, while MgO enhanced the diffusion coefficient of Al₂O₃. The results showed that the optimized matching of flexural strength (454 MPa), fracture toughness (6.97 Mpa·m^1/2), microhardness (2568 HV), and density (3.975 g·cm⁻³) was acquired by ZTA ceramic with a MgO content of 0.75 vol%.The reaction at the grain boundaries produced MgAl₂O₄, which improved boundary strength and prevented abnormal grain growth through a pinning effect, thereby enhancing the mechanical properties of the ceramic components. An appropriate amount of MgO not only reduced the uneven distribution of ceramic particles during 3D printing but also improved the surface precision and mechanical properties of the ceramic components. The research results provide foundational data for the fabrication of high-performance ZTA ceramic parts.